Method of making sheet-iron



, largely due.

IJ'NTTE STATES PATENT FFICE.

- IV. DEIVEES "WOOD, OF PITTSBURG, PENNSYLVANIA.

METHOD OF MAKING SHEET-IRON.

SPECIFICATION forming part of Letters Patent No. 310,354, dated January 6, 1885.

Application filed May 13, 1884. (No specimens.)

Z" 0 all whom it may concern:

Be it known that I, IV. Dnwnns Wool), a citizen of the United States, residing at Pittsburg, 1n the county of Allegheny and State of Pennsylvania, have invented or discovered certain new and useful Improvements in the Manufacture of Planished Sheet-Iron, ofwhich improvement the following is a specification.

In Letters Patent No. 291, 260, granted to me January 1, 1884,, I describe and make claim to certain improvements in the process of manof a red oxide, and after which the sheets in packs were heated androlled to about the gage required in the finished product, and

they were thentreated first by packing in charcoal and baking and then by superheated steam, followed by heating and hammering, all substantially as set forth in said patent. The article thus produced possessed a highlyfinished dark-blue glossy surface, perfectly or almost perfectly uniform in tint and glance. In such manufacture it has been usual to employ chilled-metal rolls having hi ghly-p olished surfaces, and to the use of such. rolls the presence of the uniform fine smooth surface is In this kind of product a fin fished surface somewhat mottled in appeariance is desirable, as thereby not only are its salable qualities improved, but also, I find, that under some conditions of use it is more durable and lasting. I have discovered that by varying this process in so far as to roll a portion of the sheets, say about one-third, (more or less,) by the use of soft rolls, or rolls made of mixed or mottled pig metal, thus reducing them from, say, No. 20 wire-gage to or approximately to the gage of the finished pro ducts, I secure on such sheets a roughened effect or mottled appearance, such that by then packing these soft-rolled sheets between the hard-rolled sheets the desired mottled or dappled elfect or appearance may be imparted to the whole pack, or to all the sheets of the pack; hence, in working the present invention, and commencing at the point indicated, I employ one, two, or more trains of rolls,

sufficient in number for the rolling and reducing of, say, two-thirds of the sheets, (more or less,) such rolls being chilled and having each a highly-polished surface. For the rolling and reduction of the rest of the sheets, say

and'so on in succession until the pack is com' pleted, after which the operations of baking, cleaning, &c., are carried on as described in the patent above referred to, or in other manner, as may be desired; but in any event the operation of hammering and heating alternately must be employed to get the desired finish, or, in other words, after the baking is done the sheets are to be hammered, either with or without some other intermediate treat ment, so that as a result of heating and hammering the desired planishcd surface may be produced; I have found in practice that with the sheets thus alternately arranged the mottled effect imparted to the soft-rolled sheets will in the final hammering be transferred, in part at least,to the hard-rolled sheets; and still further, the hard-rolled sheet-s reacting 011 the soft-rolled sheets lessen or reduce the mottled effect previously imparted to them by the soft rolls. Consequently it will be seen that I secure in this manner a uniform mottled effect, not excessive inamount or degree, and one closely approximating or identical with that found in imported Russia sheet-iron.

NVhile I believe the best results are secured by proportioning the sheets one third and two thirds, and alternately arranging them by twos and ones, as above stated, I. do not limit myself in this regard to any definite proportion,

as good results may be attained by changing these proportions to one-fourth and threefourths or one-half and one-half, or otherwise, as may be desired; nor do I limit myself as regards other features of the process, such as the artificial formation of an oxide before rolling or the use of steam after rolling, it only being essential that after the breakingdown operation, and before the final baking, some of the sheets be worked or reduced on soft rolls, so as to give the desired mottled surface thereon and the rest of the sheets be worked and reduced on hard-chilled rolls, and that such sheets be alternately arranged in any desired order or number preliminary to baking or heating and final hammering, or an equivalent finishing operation by the use of rolls.

nately arranging such sheets in packs preparatory to final hammering or rolling,

substantially as set forth.

In testimony whereof I have hereunto set my hand.

\V. DEXVEES W'OOD.

Witnesses:

R. H. WHirrLEsEY, DARXVIN S. WoLoorr. 

